Diving apparatus

ABSTRACT

An underwater deployment and storage apparatus for a diving bell or the like has a reel assembly (7) with spaced flanges (9,10) to contain an umbilical services assembly (5) wound around a hub (7A) of the reel. A rotary union (12) mounted in the hub has a fixed assembly or static line (11) about which the hub rotates. The fixed assembly receives services such as gases, liquids, electricity, fibre optics and the like and feeds to a rotatable assembly connected with the hub. The umbilical services are coupled to one of the umbilical. A first drive motor rotates the reel in either direction. A second drive motor and fairlead (6) extract from or rewind the umbilical onto the reel. Both drive motors are synchronized under controls to exert and maintain either a tractive or a drag force on the run of the umbilical.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to diving apparatus.

2. Description of the Prior Art

This invention is primarily, but not essentially, concerned withcommercial air breathing diving at depths down to 50 m and apparatussuch as are disclosed in British Application GB 2182967A to David W.Kirkley et al., and published on May 28, 1987.

SUMMARY OF THE INVENTION

In diving operations life-support and other required services aresupplied to a diver by means of an "umbilical" comprising a flexiblebundle of ducts and cables paid out from a diver deployment device orsurface support station. Such a system is not ideal.

This invention seeks to provide an apparatus for storage and feed orretraction of an umbilical under diver control and for sub-aquadeployment.

According to this invention there is provided a deployment, retrievaland storage apparatus for an umbilical, said apparatus comprising a reelwith spacer flanges to contain the umbilical assembly wound around a hubof the reel, a rotary union mounted in the hub having a fixed assemblyabout which the hub rotates, said assembly receiving services andfeeding same to a rotatable assembly connected with the hub and couplingsaid services to one end of the umbilical, first drive means to rotatethe reel, second drive means coupled with a fairlead for driving theumbilical for deployment or retrieval, both said drive means beingcoupled and controlled so that a substantially constant tractive or dragforce is exerted and maintained on the umbilical between the fairleadand reel. Both during extraction from and rewinding onto the reel.

This invention provides including the aforesaid apparatus mounted on adiving bell or the like.

The rotary union preferably comprises a first unit providing fluid lineconnections for gases and liquids and a second unit integral therewithproviding electrical and/or fibre optic connections. The two units aretypically positioned on the hub axis in end to end relationship.

The reel flanges may be spaced to provide a monospiral winding oralternatively the reel flanges are spaced to provide a multi-turnmulti-layer arrangement with three windings being an advantageous width.

The drive means may use hydraulic motors under control of the diver whomay have advance or retract control selection, alternatively air orelectrical drives could be used.

It has been found in practice that a tractive force needs to be appliedbetween the fairlead and reel as well as providing drive through thefairlead. One means for achieving this, broadly, uses a hydrauliccircuit giving proportional control with flow being divided between thefirst reel drive means and the second fairlead drive means. The fairleadmotor drive has a torque control system whereby the constant tractiveforce pulling against the reel motor drive drag is provided duringunwinding with a smaller tractive drag against the reel motor drivebeing provided during reeling-in.

Control means may be provided which adjusts. continuously or step-wise,the speed of the reel according to the instantaneous wound umbilicaldiameter.

In practice it has been found important to provide the two drive meanswhich are co-ordinated to provide the required power to overcome dragand friction without overstressing either the apparatus or theumbilical.

Encoding means may be included to determine the extracted length of theumbilical for control or monitoring purposes.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate embodiments by way of examples andare described hereinafter in outline, i.e., various features ofconstruction and operation are clearly shown on the drawings and aretherefore not described in detail.

In the drawings:

FIG. 1 shows two umbilical reeling apparatus on a wet diving bell, andin front elevation,

FIG. 2 shows a side elevational view of the apparatus of FIG. 1,

FIG. 3 shows a sectional detail through one reel,

FIG. 4 shows a side view of the reel shown in FIG. 3,

FIG. 5 shows a longitudinal sectional view through a modified fairlead,

FIG. 6 shows a transverse section through the fairlead of FIG. 5,

FIG. 7 shows in side view a modified reel,

FIGS. 8 to 10 show respectively, plan, side and front elevations of aconstruction with two single layer winding reels, and

FIG. 11 shows a hydraulic circuit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The primary purpose of the present invention is to provide anarrangement for supplying divers with a variety of services and lifesupport systems to facilitate their work many meters from a diving bellor the like using an umbilical arrangement. To prevent hazardoussituations arising the umbilical is under control of the diver and maybe stowed or paid-out in response to a command given by the diver. Asecondary means of control may be made available to a supervisor at thesurface.

Referring to FIGS. 1 and 2 of the drawings these show a wet diving bellsimilar to that described and claimed in GB 2182967A. The diving bell 1includes closable access apertures 2 and 3 with a support structure 4depending beneath the floor of the bell. To facilitate the diverscarrying out their tasks an umbilical assembly 5a is provided throughwhich various fluids and gases can be conveyed together with electricsignals for communications. The umbilical 5 passes through a fairlead 6and is wound up on a rotatable reel assembly 7. Two such assemblies withindividual umbilicals are provided to serve two divers associated withthe bell 1. Each of the reels has side flanges 9 and 10 between whichthe umbilical may be wound around the hub 7a providing for a width whichaccommodates three turns. Services to the diver are fed via a staticline or fixed assembly 11 into the centre of the reel hub and by meansof a suitable rotating union the services pass to coupling 12 whichfeeds the end of the umbilical 5.

Referring to FIGS. 3 and 4 of the drawings, the reel assembly 7 isrotatably mounted on a fixed central hub 13 which is suitably secured tothe platform structure 4. Between the inner periphery of the hub and thehub 13 a bearing 14 is provided. To the inner flange 10 of the reel asprocket wheel 15 is attached and this is engaged by a sprocket orpinion gear 16 powered by a first drive means constituted by a hydraulicmotor 17 mounted on support 17a secured to the fixed hub 13. A hubmember 8 has an outer flange portion secured to the outer flange 9 ofthe reel and an inner flange portion carries the rotating part of therotary union 18. This union 18 includes feed segments 19 each of whichcommunicate with fixed couplings for the supply of fluid to thereaftercommunicate with the lines 12 which rotate with the first rotary union18 and which supply the umbilical 5. Mounted on the same axis as thepart 18 is a second rotary union 20 which serves to supply electricalconnections to a coupling 21 again mounted on the first rotary union 18.By this means both fluid and electrical connections can be passed fromfixed conduits and cables secured to the platform structure 4 to feedthe end of the rotating umbilical 5 wound on the reel. As shown in FIG.4, a pivoted arm 53 having a roller 54 at one end engages the outerperiphery of the umbilical and associated with the arm 53 is a limitswitch assembly 58 which is preset so as to detect an upper and lowerlimit for the roller 54 whereby the drive may be shut off when theumbilical is either fully wound on to the reel or fully extracted.

In a further embodiment (not shown) the switch assembly 58 is replacedby a proportional sensing device which is able to determine the diameterof the stored umbilical on the reel at any instant and thereby indicatethe amount which has been run out. In yet another embodiment the rollerassembly, or similar arrangement, may be used to determine theperipheral diameter and thus to control the motor speed to provide aconstant rate of paying out or reeling in the umbilical.

FIGS. 5 and 6 show the fairlead drive means which has a guide cone 67adjacent the reel and through which the umbilical 5 passes. Theumbilical extends through the fairlead and passes out through a widerbell shaped guide 68. The umbilical is driven by a hydraulic motor 60which rotates a pulley 61 driving a belt or band 64 extending around afurther tensioning pulley 62. The belt has a concave surface engagingthe umbilical 5. Idler wheels 63 are provided positioned between thepulleys 61 and 62 thereby to provide good frictional contact between thedrive belt 64 and the outer periphery of the umbilical 5. In order tomaintain contact between the umbilical and the belt further springloaded pulleys 66 are provided each having an arcuate circumferencecorresponding to the outer circumference of the umbilical 5 and eachfurther being urged by spring loaded carriers 69 into firm contact withthe umbilical.

FIG. 7 shows a further modified reel construction wherein the umbilical5 is wound in a single helix between the appropriately spaced slideplates 9 and 10. This arrangement provides less accommodation for theumbilical for a given diameter but does prevent loosening of the turns.The construction shown embodies an inwardly facing gear ring 15 drivenby a sprocket 16 on hydraulic motor 17.

There may be included a multi-turn potentiometer driven by or from thewheel to provide an electrical signal proportional to the length ofumbilical paid out.

FIGS. 8 to 10 show the complete single turn umbilical reeling meansfitted to a wet diving bell and indicates one preferred construction ofa complete diving apparatus. Reference numerals designating the partsare as previously used. As may be seen from this construction, oneadvantage of the arrangement is that the reel containing the umbilicalis positioned so that there is very little increase in size and volumeof the overall diving apparatus and the reel is not an encumbrance tonormal diving operations.

FIG. 11 shows an outline hydraulic circuit using variable/axial pistonpump 100 with associated controlling valve gear. The output of the pumpis fed to a reversing proportional valve 101 which in turn feeds via aflow divider 102, the main reel motor drive 103 and the fairlead motordrive 104. Each of the drives 103 and 104 has a respective relief valvesystem 105 and 106 which may serve to control torque such that thetractive or drag force between the main reel and the fairlead aresubstantially constant. A further important feature of the hydrauliccircuit is that overtensioning of the umbilical is prevented byutilising torque limiting systems. In both the drawing-out of theumbilical and the reeling-in it has been found in practice that frictioncan become very heavy and for this reason it is a feature of thisinvention to provide drive to both the main reel and the fairlead butstill maintaining an amount of tension through the torque control meansto prevent spilling the umbilical from the reel.

The valve systems 105 and 106 further provide overload relief meansoperative to prevent excessive forces being applied to the umbilical if,for example, the diver is trapped or the umbilical is snagged.

To prevent reeling-in over-run beyond a certain point a rubber wedge maybe secured to the umbilical to abut the fairlead and physically preventfurther winding-in, thus stalling the motors and causing relief valvesand 106 to operate.

The subsea umbilical wheels are powered by two hydraulic motorscontrolled by a hydraulic power pack on the support vessel, whichcontrols the flow, pressure and direction of rotation.

On paying out of the wheel, both motors 103,104 are poweredsimultaneously to turn the reel and drive the fairlead, the fairleadbeing used to pay out the umbilical to the diver and prevent slack turnsdeveloping on the drum by keeping tension on the umbilical it all times.

On reeling in, only the main wheel turns to stow the umbilical with thefairlead motor free-wheeling under tension to apply drag to theumbilical tight on the drum at all times, with a restricted line pull toprevent diver injury.

On selecting direction of control oil flows from pump 100 through lines"P" and "A" of the proportional directional valve 101 to "P" port of theflow divider 102 where the oil is split 60/40% to fairlead 104 and wheelmotor 103. The fairlead motor has priority on drive due to thesequencing valve 107 delaying pressure to the wheel motor 103 until thefairlead motor 104 is up to pressure and running, and then the sequencevalve 107 opens giving drive to the wheel.

Speed of the wheel can also be controlled by adjustment of the speedcontrol valve 106 to slow or speed up the wheel accordingly and alsohelp in synchronisation of the fairlead drive should the wheel pay outtoo quickly. Oil then returns to port "B" of directional valve and backto the tank.

On recovering the umbilical, oil is selected between ports "P" and "B"of valve 101 and flows at a reduced line pressure, due to the reliefvalve 110, to limit the line pull to 50 kg at the bottom turn. The flowthen enters port "A" of the wheel motor 103 and in turn opens the pilotcheck valve 120 to prevent cavitation of the fairlead motor 104.

From motor 103, oil enters the speed control valve 105 to control thespeed of the wheel, if desirable, and then bypasses both 107 and 102back to port "A" of 101 and finally back to tank 130.

A means may be provided to prevent over-run in the unwinding directionthus preventing the umbilical from being reverse wound should the limitswitch fail to operate.

Although the embodiments described and shown with reference to thedrawings use reels mounted in a vertical plane, it is equally possibleto mount the reels in a horizontal or other plane should this be moreconvenient in any particular construction.

We claim:
 1. An underwater deployment, retrieval and storage apparatusfor an underwater umbilical, said apparatus comprisingan underwater reelwith spaced flanges to contain the underwater umbilical wound around ahub of the of the reel, a rotary union mounted in the hub having a fixedassembly about which the hub rotates, wherein the rotary union comprisesa first unit providing underwater fluid line service connection forgases and liquids and a second unit integral therewith providingunderwater electrical service and fibre optic connections, said fixedassembly receiving services from said service connections and feedingsame to a rotatable assembly connected with the hub and coupling saidservices to one end of the umbilical, first drive means to rotate thereel, second drive means coupled with a fairlead for driving theumbilical for deployment and retrieval, and both said drive means beingcoupled and controlled so that a substantially constant tractive or dragforce is exerted and maintained on the umbilical between the fairleadand reel during extraction from and rewinding onto the reel in anunderwater environment.
 2. An underwater apparatus according to claim 1,wherein the reel flanges are spaced to provide a mono-spiral winding. 3.An underwater apparatus according to claim 1 wherein the reel flangesare spaced to provide a multi-turn multi-layer winding.
 4. An underwaterapparatus according to claim 1, wherein the first and second drive meansuse hydraulic motors under remote control having extraction andrewinding control selection.
 5. An underwater apparatus according toclaim 1, wherein the first and the second drive means are controlledwhereby, during extraction, the second drive means extracts theumbilical against the drag of the first drive means.
 6. An underwaterapparatus according to claim 1, wherein the first and the second drivemeans are controlled whereby, during rewinding, the first drive meansretracts the umbilical against drag of the second drive means.
 7. Anunderwater apparatus according to claim 1, wherein the first and seconddrive means comprise hydraulic motors in a hydraulic circuit givingproportional control with flow being divided between the first drivemeans and the second drive means.
 8. An underwater apparatus accordingto claim 1, wherein the second drive means has a torque control systemwhereby the constant tractive force pulling against the first drivemeans is provided during extraction with a smaller tractive drag againstthe first drive means being provided during rewinding.
 9. An underwaterapparatus according to claim 1, including control means which adjusts,continuously the speed of, or torque applied to the reel according tothe instantaneous wound umbilical diameter.
 10. An underwater apparatusaccording to claim 1, wherein a mechanical pivoting arm stop meansengages the reel at limit positions of extraction and rewinding of theumbilical.
 11. An underwater apparatus according to claim 1, wherein thefirst drive means comprises a driven pinion engaging an annular geartrack on one of the flanges of the reel.
 12. An underwater apparatus inaccordance with claim 1, wherein both the first and second drive meansare operative both during extraction and during rewinding of theumbilical, the respective drive rates and torque applied through eachdrive means being arranged to maintain a traction in the umbilicalbetween the fairlead and the reel.
 13. An underwater apparatus accordingto claim 1, wherein the second drive means is effected by frictionalengagement between a peripheral part of the umbilical and a linearlymoving drive member.
 14. An underwater apparatus according to claim 13wherein the drive member comprises an endless belt extending betweenrollers, one run of the belt engaging the umbilical.
 15. An underwaterapparatus according to claim 14, wherein the belt has a concave surfaceprofile engaging the umbilical.
 16. An underwater apparatus according toclaim 14, wherein the umbilical is pressed against the belt by rollers.17. An underwater apparatus according to claims 14, wherein the drivemember includes a second belt engaging and pressing against theumbilical in opposed relationship to the belt.
 18. An underwaterdeployment, retrieval and storage apparatus for an umbilical, saidapparatus comprisingan underwater reel with spaced flanges to containthe underwater umbilical wound around a hub of the reel, a rotary unionmounted in the hub having a fixed assembly about which the hub rotates,said fixed assembly receiving services and feeding same to a rotatableassembly connected with the hub and coupling said services to one end ofthe umbilical, first drive means to rotate the reel, second drive meanscoupled with a fairlead for driving the umbilical for deployment andretrieval, both said drive means being coupled and controlled so that asubstantially constant tractive or drag force is exerted and maintainedon the umbilical between the fairlead and reel, both during extractionfrom and rewinding onto the reel in an underwater environment, andincluding encoding means to determine the extracted length of theumbilical for drive control or monitoring purposes.
 19. A marine divingbell includingan underwater deployment and storage apparatus for anumbilical, said apparatus comprising at least one underwater reel withspaced flanges to contain the underwater umbilical wound around a hub ofthe reel, a rotary union mounted in the hub having a fixed assemblyabout which the hub rotates, said fixed assembly receiving line servicesfor gases, liquids, electricity, and fiber optics, said line servicesbeing fed to a rotatable assembly connected with the hub, and couplingsaid services to one end of the umbilical, first drive means to rotatethe at least one reel, second drive means coupled with a fairlead fordriving the umbilical for deployment and retrieval, both said drivemeans being coupled and controlled so that a substantially constanttractive or drag force is exerted and maintained on the umbilicalbetween the fairlead and the at least one reel, both during extractionfrom and rewinding onto the at least one reel in an underwaterenvironment; and including encoding means to determine the extractedlength of the umbilical for drive control or monitoring purposes.
 20. Amarine diving bell according to claim 19, wherein the at least one reelof said underwater deployment and storage apparatus is mounted to a sideof a diving bell, the plane of the at least one reel being vertical. 21.A diving bell according to claim 19, wherein the at least one reel ofsaid underwater deployment and storage apparatus is mounted below adiving bell, the plane of the at least one reel being horizontal.